Characterization of Banana SNARE Genes and Their Expression Analysis under Temperature Stress and Mutualistic and Pathogenic Fungal Colonization

SNAREs (soluble N-ethylmaleimide-sensitive-factor attachment protein receptors) are engines for almost all of the membrane fusion and exocytosis events in organism cells. In this study, we identified 84 genes from banana ( ). Gene expression analysis revealed that the expression of s varied a lot in different banana organs. By analyzing their expression patterns under low temperature (4 °C), high temperature (45 °C), mutualistic fungus ( , Si) and fungal pathogen ( f. sp. Tropical Race 4, TR4) treatments, many were found to be stress responsive. For example, was up-regulate by both low and high temperature stresses; was up-regulated by low temperature but down-regulated by high temperature; and TR4 treatment up-regulated the expression of but down-regulated and . Notably, the upregulation or downregulation effects of TR4 on the expression of some could be alleviated by priorly colonized Si, suggesting that they play roles in the Si-enhanced banana wilt resistance. resistance assays were performed in tobacco leaves transiently overexpressing , and . Results showed that transient overexpression of and suppressed the penetration and spread of both 1 ( Race 1) and TR4 in tobacco leaves, suggesting that they play positive roles in resisting infection. However, the transient overexpression of facilitated infection. Our study can provide a basis for understanding the roles of in the banana responses to temperature stress and mutualistic and pathogenic fungal colonization.